In article ,
Bob Johnson wrote:

Our engine is petrol fueled. Despite Google's best efforts, I have not
yet located a Torque/HP/RPM curve for our very common 7.4 L engine, but
have heard that it develops max torque and HP at about 3000 RPM and
further that the curves are fairly flat at this point.

You are making some totally contradictory and inconsistent claims there.

If max torque and max HP occur close together then they must both drop
off precipitously after that.

If the torque curve is flat then HP will be increasing linearly with
RPM, max torque and max HP will be very far apart.


It is quite likely that you do have maximum torque at around 3000 RPM,
but if for example the torque curve is flat enough that the torque at
the 5000 RPM redline is still 60% or more of that at 3000 RPM then that
(redline) is exactly where maximum power will be.

-- Bruce